johnnychemo

How do I determine how long to fly before it is time to bring it in? To be specific, I bought the Parkzone Corsair. It comes with a 480 brushless outrunner motor. I also picked up a 11.1v 3S1P 2200mAh 20C lipo to run it on. I've flown glow planes for a number of years now, but this is my first foray into electrics. I've gotten a lot of good info from this site as well as a few others, but I've yet to come across that magical "how long can I fly" formula. Thanks for any help!

Larry3215

Your batteries will last longer if you only use about 75% - 80% of their capacity on any given flight. So if your packs are 2200 mahr you should only use about 1800 mahr max.

The easiest way to keep track of this is when you re-charge. I would make a short flight and time it. Then when you re-charge note how many mahr were put back into the battery by the charger. Adjust your flight time accordingly.

If your charger does not tell you how much you put back into the pack, then that makes it more dificult.

You can either buy a better charger or get a Watt meter and use that in between the battery and charger. All electric flyers really should own a Watt meter anyway. Its the most valuable electric flying tool you can own.

You can also check the pack voltage after a flight but that requires a moderately accurate volt meter and you need to wait untill the packs voltage has stabilized - at least 4 or 5 minutes after the flight. Id fly down to no more than about 11.2 to 11.3 resting volts on the pack. This last method is the least accurate.

johnnychemo

Thanks!

Oh, and I bought a Cellpro 4S charger, based on the rave reviews I've read here and at RCGroups. IIRC, that will show how much it puts back in, won't it? (None of my new toys have arrived yet!)

Larry3215

Yes, thats an excellent charger and it will tell you all you need to know about your packs. Id still recommend a Watt Meter though

johnnychemo

I'll add it to the list! Thanks again!

AEAJR

Even with all the meters and gagues it is still a matter of test and time. YOu don't typically fly at one speed all the time so your power use will vary over the flight.

Try 5 minutes and see how much you put back. Then estimate the next flight and see if you can push it further.

If your plane has a good glide, take it all the way to cut off and see how long you got. Now, was that a typical flight?

johnnychemo

Thanks! I thought it might be an evolving process, but I was hoping to find a somewhat concrete approach to it.

AB Bob

Ed.
I know you've heard it before, but not from me. THANK YOU for all the knowledge you have put down in print for newbies like me! You are an asset to this, and many other forums as well!
Bob

AEAJR

Thanks Bob. Glad I could be helpful.

Matthardy

Hi
Your sit makes it easy to do quick refresher info Thanks.
Thought you would like to know your links to Maxxproducts don't work.
Ernie

AEAJR

Thanks Earnie. It takes a lot of time to maintain links. Now that I know that some are broken I will try to update them.

gary p

Hi Ed and thanks for all the great information. I am new too and it's helped my understanding of RC aircraft alot especially motors and batteries.

And thanks to Tim for the pdf file.

Cheers

Gary

SARG5

Thank you
Have not had time to real very much. But this looks like the information I am looking for.
I am still trying to get my old Nitro going again. Have been trying to get good information on E-flight. I have been getting VERY BAD INFORMATION FROM MY LOCAL HOBBY SHOPS, and the OLD TIMERS in Nitro.
They say Batteries cost $400.00 Will last only about 50 flights , Motors will not pull a large Trainer in our Kansas winds, etc . etc.
I will keep reading.
SURE WISH I HAD A COMPLETE COPY OF YOUR KNOWLEDGE.

SHERWIN STIELOW
SEEING THE COUNTRY WE DEFEND

mred

I don't know what kind of batteries they are using, but it is easy to spend $400.00 on batteries if you get the most expensive batteries on the market. I buy the Cheaper Zippy batteries from Hobby City and they are much less expensive then ThunderPower batteries and they WILL last more then 50 flights IF you take care of them. BY that I mean, don't discharge them below 80% to 90% and the best is 80%. I have batteries that I have more then 200 flights on and they are still going strong.

Motors will out pull a nitro engine, so if they fly with nitro, you sure as heck can fly electric. They are just die hard glow guys giving out that information and it's bad information.

As for an easy way to tell if your batteries are ready to be brought down, there are a couple of systems you can add to your battery that will tell you that you are at low voltage before your ESC cuts off. They have a nice bright LED on them and if you rough it up with 400 sand paper, it will show up better. Most LED are directional and the sanding makes them much less dorectional. Some you can set for a given viltage and it will turn on the LED when you reach that voltage under load. I have one and it works great. I land when it comes on and when I recharge, I normally put around 75% back in the battery if I let it go all the way and the light comes on. Most of the time I don't, so I put less back in. It also gives you more time to land then the ESC cutoff does.

Don't believe everything you hear from the die hard glow guys. Some of them hate electric so much they will give you bad information just to keep you off electrics. They just plain don't like them. Electric motors of the same size rating of a glow will pull harder then a glow enging and you don't have to worry about a dead stick landing even if you go to ESC cutoff.

Just remember one thing. Glow guys buy their fuel in gal containers and spend $20.00 or so a gal. You buy a battery for $100.00 and buy the time you get it used up, you will get more flying time out of it. You pay for your fuel up front instead of a little at a time, but in the long run, I think batteries are cheaper, unelss you like burning up batteries like some people do.

Ed


PS. Not all batteries cost $100.00. It depends on the size and how many you need to put in the plane to run the motor right. Most of the time I use a 2200MAh battery and they cost around $25.00 or so and they last a long time. I payed $102.00 for a 4S 5000MAh battery and that is not what I normally fly with. Most of the batteries I fly are between $25.00 and $50.00, so figure out what that cost per flight with about 500 flights IF you take care of them. Your battery changer is a great changer. I have one and it's great. I love it.

AEAJR

The goal of an e-book thread like this is to try and capture the community knowledge in one place. Glad you have found it helpful.

As for $400 batteries, wellllllll, that depends on how big the plane is. Certainly if you are going to try and fly a 25 pound 1/4 scale something or other that was converted from glow, you could end up paying a lot more than $400 for batteries. But the typical electric pilot is flying planes under 10 pounds and I would bet a good 75% are flying planes under 6 pounds. So batteries are not the huge expense they once were.

Note that glow planes, less servos and power systems, are typically heavier than planes built for electric flight. The glow planes have to deal with vibration and fuel effects that electrics don't face so we our planes can be build lighter.

Electric powered planes can run with any glow plane as long as you put in the right set-up.

Batteries last according to their quality and how well you treat them. ALWAYS balance Lipo packs. Do this and they will last much longer. And don't over discharge them. Set your LVC for 3V per cell and you should be fine.

There was a time, maybe 7 years ago, when what they said was probably true. But in the world of electric flight, that is 3 generations ago. Glow has pretty much been stagnant for years, but electric is advancing at a breakneck speed.

What we know today about electric flight will be out of date 3 years from now. But glow will be about the same as it is today. It is a mature technology, well proven and well understood, but, as far as I understand it, not advancing much.

Keep reading, keep learning, keep asking questions.

SARG5

Not sure what you mean by ALWAYS BALANCE LIPO PACKS. and Set our LVC for 3V per cell.
See you lost me quick
Stielow
SEEING THE COUNTRY WE DEFEND

AEAJR

No Problem. The first step to knowledge is admitting you don't know something.

Remember this is a e-book thread. There is a book index at the begining of the thread.

Go to the first post and read the table of contents. Your questions are answered in chapter 6 ( post 6) and chapter 11 ( post 11 ).

Read the chapters and see if this becomes more clear. If you have more questions, feel free to ask. If you found the chapters helpful, let us know.

mred

I just returned from a weekend at SEFF, which is the Southeastern Electric Flight Festival and you would not believe what they are flying on electric now. Anything and everything. They had 50cc planes flying on electric and THEY along with the 12 foot Telemaster and planes like them are the ones that take more then $400.00 for batteries. In fact, they had one out there that took $3000.00 in batteries, but that is NOT the normal plane. The average plane that most people are flying take about $50.00 to $200.00 in batteries and that is the batteries like Thunder Power. Using the Zippy type batteries I can get away with $25.00 to $100.00 depending on the plane. And talk about power, you would not believe the power they put out with the new motors.

There is one thing that you have to REALLY watch with electric planes. A glow powered engine will stop if it hits your hand, but an electric motor will keep right on trucking. That is one thing you must watch on electric power. The motor is still drawing power from the battery even if it hits your hand, so it can chop it up pretty good. You have to really be careful around them for that reason.

If nothing else, this is the one safty lesson you need to learn and NOT the hard way. When ever you are working on an electric plane, ALWAYS take the prop off. You would not believe how bad a small motor can eat your hand if it is turned on at the wrong time and the motor will NOT stop unless it is a very small motor. I always take my prop off unless I am flying. Any other time you don't need a prop on it anyway.

As for power, the 50cc planes were flying 3D just as good if not better then the gas version. Also, the planes are getting lighter with electric power. The same plane in gas form weighs 24lbs, but the electric plane comes out at 18lbs. This is the same plane, different power system.

In short, the new electric planes are flying just as good if not better then the nitro versions and really has more power if you use a power 46 to replace a .46 glow engine. There have been a lot of advancements in glow, but not as fast as the electric systems. It is new and is bound to advance fast at first.

Don't be afraid to ask questions and read all you can on electrics. There is a whole new world out there and it is kind of hard to keep up, but it's not as hard as some people make it out to be. Just like everyone else, you have a steep learning curve at first, but once you get it figured out, it's not really any harder then glow, just different equipment. Some of the OLD glow guys are die hard glow and can't or won't learn the new stuff, but that doesn't make it hard, it just makes it hard at first. Look at what other people are using on their planes and you can get a good idea of what to use on yours.

Once you learn the watts per pound rule, the rest is sort of easy. You need to learn a lot of things, but look at it this way. No one new all of this information the first day they started, they had to learn too. I'm an old glow guy and started out in electric 3 years ago and I had to learn everything too. If I can do it, so can you. I've been flying since the middle 50's and started on C/L using glow simply because we didn't have electrics to fly then, but I go either way now. I fly glow and electric and it's just different, but not really all that hard. Just look at it as another challenge and start reading all you can and asking questions and you too can be out there flying and having a ball on electric power.

Also, like glow or gas, it no more expensive then you want to make it. I can have a plane flying for under $100.00 on electric buying everything except the radio, or I can put over $5,000.00 into one easy. It all depends on your budget and what you want to put in it. Not all planes cost an arm and a leg - some only cost a finger.

Ed

AEAJR

Great post Ed.

mred

Thanks Ed.
Even though I have been flying electric for 3 years now, I am still not afraid to ask questions and often do. One thing I have learned about anything and that is that no one person can know it all. I'm just happy if I can keep myself out of trouble.

Ed

AEAJR

Oh, I know everything.

Except when someone shows me something I don't know. But once I know that, THEN I know everything!

mred

I'm the same way.... Trouble is, every time I leave the house, I run into someone that shows me something I don't know.

Ed

ChrisW

i've yet to give this a really good read, but the bits i've gleaned so far looks like it will really help, i've been out of the hobby for quite some time and i'm slowly coming around back to it. (hopefully this time i will not have to use up so many trainers ) i'm likeing the idea of electric flight mainly due to the messyness of the old birds i flew, & the small space i now have. when i get to actuall building i'll hit you up with a lot of questions, till then thanks for posting this

-Chris

noffey

If I have a plane that takes 18volt battery, is there any advantage to having a single 18 volt battery over a 7.6 plus a 11.4

cbatters

Worth posting the question in the battery / charger area for a quick response.

http://www.wattflyer.com/forums/forumdisplay.php?f=6